(AP Photo/Paul Sancya)
Sandra Layne begins to testify in the Oakland County Circuit Courtroom of Judge Denise Langford-Morris in Pontiac, Mich., Wednesday, March 13, 2013. Layne, 75, is charged with first-degree murder in Oakland County court. There's no dispute she repeatedly shot 17-year-old Jonathan Hoffman last year in West Bloomfield Township, even while he called 911 for help. Layne's lawyer says she feared for her life because of Hoffman's erratic behavior and his use of synthetic marijuana.

Sandra Layne said she never intended to hurt or kill her grandson and will be in mourning for the rest of her life, no matter what verdict the jury reaches.

Layne, charged with open murder, recounted the struggle that led to the shooting death of her grandson, 17-year-old Jonathan Hoffman, at their West Bloomfield Township condominium last May.

Layne, 75, said Hoffman was "angry" after testing positive for Spice -- or K2, as it has been known, a so-called synthetic marijuana that has since been banned by the state -- earlier in the day and was concerned that he'd be going to jail on a probation violation for a prior misdemeanor drug charge. On the way back from the test, he repeatedly attempted to take control of the vehicle Layne was driving them in, she recounted.

She initially agreed to give Hoffman $2,000 in cash so he could leave town and avoid jail, but, while driving to an ATM, she said she decided against it.

An argument ensued in Hoffman's loft bedroom, and Layne became frustrated as Hoffman said he was taking her car and leaving.

Watch coverage of the ongoing trial on today's News at Noon.

Layne went to retrieve her gun because "I wanted him to hear me. I wanted him to pay attention to me."

Upon returning to the loft bedroom with the gun, the argument continued.

"He kicked me," Layne said, becoming emotional on the stand. She said she was "startled" and was concerned that she would be injured.

Layne shot the gun -- she's not sure how many times -- and there was a struggle. Layne ran down the stairs, as did Hoffman. She continued shooting and ran to the basement, to a spot where she thought Hoffman would not find her.

When asked how long she was down there, Layne said "It seems like there is no time. Time, it doesn't exist. It's running. Hysteria."

Layne said she could not hear well because of the effects of the shooting, but she thought Hoffman may have needed help.

"I go up to the loft, he's there, and I can't hear what he's saying," she said. "I put down the gun and I go over to talk to him."

Hoffman reached for the gun but Layne grabbed it and continued to shoot.

Her defense attorney, Jerome Sabbota, asked "Why are you shooting?"

"I don't know," Layne said. "You just do."

After firing the additional shots, Layne could be heard in the background of the 911 call Hoffman made asking Hoffman if he wanted some water.

"I think he's asking me for water," she said, explaining that her hearing was still not functioning well.

"It's bizarre. I still hear him. There's smoke in the house. I still can't hear well. I see police outside the house and I hear them saying 'Open.' I tried to ask them what to do. Do I put down the gun?"

Layne was not sure if any of the shots hit Hoffman. Five bullets entered his body, while a sixth grazed his shoulder, medical examiner testimony revealed.

Sabbota asked Layne if she wanted this result.

"Of course not," she said. "I still love him."

After a recess, Oakland County Assistant Prosecutor Kelli Megyesi began to cross-examine Layne.

Megyesi mentioned that Hoffman had an aunt who lived in the area.

"Instead of sending him home, calling his Aunt Judy, you choose to get a gun," Megyesi said. "Is that correct?"

"That was to protect our house," Layne said. "How is Judy, or his parents in Arizona, going to protect our house?"

Megyesi asked a similar question: "You chose, instead of sending Jonathan to Arizona and getting the problems out of the house, to get a gun, didn't you?"

Layne said the gun was necessary for "immediate help."

"It was a changing scenario," she said.

"It didn't start in October (when Hoffman's friends began to visit late at night) the way it ended in May. After (Hoffman was taken to a hospital in March 2012 for a drug overdose), there was an absolute tipping point."

Layne said Hoffman never assaulted her or her 87-year-old husband, Fred, before the day of Hoffman's death.

During questioning by Megyesi, Layne confirmed that there are several phones in the Layne home, and that she had a cell phone. She never made a call for help or for medical assistance for Hoffman, according to phone records shown earlier in court.

Earlier Wednesday, Layne's defense team called four witnesses in rapid succession, testifying about her grandson's probation, paraphernalia that was found in his closet and a March 2012 incident in which police were called to the Layne home.

West Bloomfield police Cadet Shelby Maranowski, who was working in the jail when Layne was arrested, said Layne was holding a cold juice box to her face as though it were an ice pack less than 12 hours after being arrested.

Layne did not describe any pain she may have been having and did not request any medical attention.

West Bloomfield Police Officer Scott Mong was next to the stand. Mong responded to the Layne home on Brookview Lane in March 2012 for an argument between Hoffman and Layne.

Hoffman's hands were in his pockets when Mong arrived. "He appeared to be very upset and he began speaking very loudly, yelling, and he was using profanity," Mong said.

Hoffman, upset about a text he received from his father, referred to his mother as "(Layne's) daughter."